Are you wearing multiple masks? Is two good?

The football coach does that. Chairman Elect does that. Even science-savvy senators do it.As in the case of Coronavirus It continues to grow rapidly on a global scale, and some of the country’s most prominent people are beginning to double. mask — The movements researchers say are increasingly backed up by data.

Double masking is not necessary for everyone. However, for those with a thin or thin face, “combining multiple layers begins to achieve a fairly high efficiency of preventing the virus from entering and exiting the respiratory tract,” said Virginia Tech’s specialty of virus infection. A recent commentary on the science behind being a home and wearing a mask.

Of course, there are trade-offs. At some point, “there is a risk of difficulty breathing,” she said. However, there is plenty of room for breathing before the mask wear approaches its extreme.

One year later COVID-19 Pandemic, the world looks very different. Over 90 million confirmed coronavirus infections have been recorded worldwide, killing millions and innumerable in ongoing financial difficulties and closed schools and businesses. I have a prolonged symptom. New variants of the virus have emerged, resulting in genetic changes that appear to enhance the ability to spread from person to person.

And while some vaccines have cleared regulatory hurdles, the deployment of injections is rapid and slow. And there is still no clear evidence that shots have a substantial effect on the rate of spread of the virus and the infected.

Throughout all that change, researchers have retained the mask line. “Americans don’t have to wear masks forever,” said Dr. Monica Gandhi, an infectious disease specialist at the University of California, San Francisco, and author of the new commentary. But for now, they need to continue to provide protection to both the mask wearer and the people around him.

The masking debate spans several scientific disciplines, including epidemiology and physics. A series of observational studies suggest that extensive mask wear can control infection and death on an impressive scale in a small environment such as a dressing shop and at the national level.

A study that tracked state policies requiring face covering in public found that known COVID cases increased or decreased almost in lock steps with mask wearing rules. Another person who followed the coronavirus infection among Boston health care workers pointed out that the number of positive test results dropped dramatically after the mask became a universal fixture among staff. did. A study in Beijing also found that face masks were 79% effective in blocking the transmission of infected people to close contacts.

Recent studies by researchers like Ma are now identifying the basis of these links on a microscopic scale. She said science is pretty intuitive. Respiratory viruses, such as the coronavirus, require a clear conduit to move between people in saliva and spray masses and into the airways that are congested with the type of cells that the virus infects. A mask that covers the nose and mouth keeps it out.

The important thing is not to make the mask airtight, Mr. Ma said. Instead, the fibers that make up the mask create an unplanned obstacle course through which air (and infectious cargo) must pass.

“The air has to follow this winding road,” Ma said. “The big things it carries will not be able to follow those twists and turns.”

Experiments testing the extent to which the mask can wayray inbound and outbound sprays have shown that even fairly basic materials such as cloth covers and surgical masks are at least 50% effective in either direction.

Some studies have reaffirmed the notion that masks appear to be better at protecting the people around them than the mask wearers themselves. “That’s because you’re stopping it in the sauce,” Ma said. However, motivated by recent research, the Centers for Disease Control and Prevention have found great benefits for those who wear masks.

The best mask remains the N95, designed with ultra-high filtration efficiency. However, there is still a shortage of healthcare professionals needed to safely treat patients.

Two less specialized masks can be layered on top of each other to provide equal protection. Marr tends to be made of a more filter-friendly material, but recommended wearing a cloth mask that hugs the face over a surgical mask that fits looser. Another option is to wear a cloth mask with pockets that can be filled with filter material, such as those found in vacuum bags.

However, wearing three or more masks, or layering masks that are already very well filtered, causes immediate diminishing returns and makes normal breathing much more difficult.

Other tweaks can improve the fit of the mask, such as a tie that secures the fabric around the back of the head, instead of relying on ear loops that allow the mask to hang or create gaps. The nose bridge, which helps to fit the top of the mask more snugly, also provides a protective boost.

Achieving a good fit and filtration is “really easy,” Gandhi said. “You don’t have to do anything special.”

There is no perfect mask. Wearing a mask does not eliminate the need for other public health measures such as physical distance or good hygiene. Jennifer Nuzzo, a public health expert at Johns Hopkins University, said:

Wearing masks remains rare in some parts of the country, partly due to the politicization of practices. But experts pointed out that model behavior by national leaders may help turn the tide. In December, President-elect Joe Biden called on Americans to wear masks for the first 100 days after taking office, calling for them to be worn on federal buildings and cross-state planes, trains, and buses. He said he would make it mandatory.

In a large review of the evidence behind masking published in the journal PNAS this month, masking is an important tool for reducing community infections and is “most effective in reducing virus spread when compliance is high.” I concluded that it was “target”.

Some messaging may require more empathy, open communication, and voice approval that “people don’t enjoy wearing masks.” Without further patience and compassion, simply doubling the limit to “fix” the loss of compliance would be counterproductive: “If no one follows, the policy won’t work.”